Panasonic Technics SL-1700

Features
Turntable section
The newly developed double-insulate vibration-damping unit,
‘unique in Technics, was developed through high mass design
placing particular emphasis on acoustic quality (See Fig. 26).
‘The turntable platter and the tonearm are installed on the base
and solidly girded through the integral construction of the main
1nd the bottom of the case, while the entire base is
‘through insulators, composed of springs and a viscoelastic
rial.
‘The base is protected against vibrations by the viscoelastic
material and is further weighted by the metallic board. The main
turntable base is also provided with an insulator superior in
vibration damping characteristics for protection trom undesirable
external vibrations. As a result, a combined effect is obtained
through the use of two insulators to maintain excellent absorp-
tion and cut-off of external vibrations and local resonance trom
speaker output thus etfecting remarkably improved feedback
prevention.
[Motor construction peculiar to Technics in which the rotor ot
{the motor is integrally connected to the turntable platter.
(See
Fig.26)
In Technics turntable systems we took the lead in the world by
pulting the Direct Drive system on the market with a marked
improvement in the performance of turntables. Since then,
We have developed numerous turntables of high portormance,
furnishing new topics of conversation each time,
One of these achievements is the motor construction of this unit,
unique and singular in the world, in which the rotor of the motor
{is directly connected to the turntable platter
Moreover. the motor base has been integrally connected to the
‘turntable base of diecast aluminum for presenting turntable
tems of higher accuracy and rational construction.
Msilont reliable auto-mechanism.
fecision-molded resin is employed in the drive section of the
aulo-mechanism to reduce distracting operating noise. Theretore
‘the load sustained by the drive system is small and combined with
the use of the highly sensitive gimbal suspension tonearm, the
unit can fully accommodate a light stylus pressure cartridge.
Mependabie one chip IC (See Fig. 27).
First in development of the 1C (AN620) of the Back Electro-
‘motive Force Frequency Generator system. The motor drive unit,
Control unit and various additional functions are integrated into
the B.FG" system which utilize the Back Electromotive Force
Frequency Generated in the drive winding of the Direct Drive
teristics are obtained improving the overall reliability of the
turntable system.
‘The one chip IG (AN630) employed in this unit has a total of $21
elements such as transistors, diodes, resistors and capacitors
consolidated in a silicon substrate approximately 3 *2.7 mm? in
size, We take pride in the fact that the one chip IC (AN630)
represents the world's largest degree of integration as a bipolar
linear IC.
* Back Electromotive Force Frequency Generator
HHi-tidelty pertormance with rumble (signal to noise ratio) of
73
dB
(DIN4SS39B),
wow
and
flutter
of
0.025%
(W.R.M.S.),
‘The
ultra-low
speed
brushless
DC motor
employed
in this
unit
‘has
the extremely
low
power
consumption
of about
0.1 W. and
is
thus
free
from
vibrations
due
to excessive
energy
or heat
‘generation.
The
high
performance
of the Direct
Drive
motor
is
‘du6'to
the efficiency
of the newly
developed
double
insulator
and
{0 the utilization
of the one
chip
IC of the
B.FG
system.
[Turntable
base
Is
of
diecast
aluminum
for
slim
and
compact
design.
Newly designed turntable rubber mat with improved record
adherence.
Prism type strobe illuminator also serves as pilot lamp.
Ht (Centre spindte)
Cross section of motor portion and double insulator
Position detecting rotor
‘Stator
Turntable mat
Position detectog cod!
Tonearm
Dust cover
Rotor magnet
Turntable platter
Turntable bas : =
It a
Spring I inf Il
4st insulator
2nd insulator sisi es
Viscoelastic materiai_| | Main base